Complete nucleotide sequence of genomic RNA of the potato M-virus

The complete nucleotide sequence of potato virus M genomic RNA has been determined to be 8534 nucleotides (with the exception of the poly(A) tail at the 3' end). The sequence contains six large open reading frames coding for proteins of mol. wt. 223206, 25438, 11893, 6793, 33906, and 12183 (in 5'----3' direction). According to its primary sequence analysis the 223K protein ORF codes for a virus RNA replicase. The in vitro translation product of 34K protein gene precipitates by the antisera against the RVM indicating that the 34K protein is the virus coat protein. The general aspects of carla- and potexvirus gene organization are discussed.     

A spin-label for RNA study

The compound 2,2,6,6-tetramethyl-4-[β-N-ethyleneiminopropionyl] oxypiperidine-I-oxyl is used as a spin-label for RNA. The reaction, effected under rather mild conditions, results in 50–70 nucleotides per spin-label. The temperature dependence of the ESR spectra of spin-labeled RNA is used to estimate temperatures corresponding to the beginning of melting, T_crit (“critical” points of the structure) and to calculate the effective activation energies of the rotational mobility of spin-labels, Δ E_eff.; the dependence of T_crit. on the ionic strength of the solution is also determined.     

Defense peptides from barnyard grass (Echinochloa crusgalli L.) seeds

A number of defense polypeptides from latent seeds of weed cereal barnyard grass (Echinochloa crusgalli L.) has been isolated and characterized using an acidic extraction and high performance liquid chromatography methods in combination with MALDI-TOF mass spectrometry and Edman sequencing. Members of three antimicrobial peptide families and two protease inhibitor families were found to be localized in barnyard grass seeds. Their biological activity concerning to Gram-Positive and Gram-Negative phytopathogenic bacteria, as well as oomycete Phytophthora infestans, has been investigated. Diversity of barnyard grass defense peptides is a significant factor that provides a resistance of E. crusgalli seeds to germination and latent phases.     

A point mutation in the coat protein gene affects long distance transport of the tobacco mosaic virus

A mutation resulting in substitution of positively charged Lys53 with negatively charged Glu in the coat protein was introduced in the infectious cDNA copy of the genome of wild-type tobacco mosaic virus strain U1. Kinetic analysis of long-distance virus transport in plants showed that systemic distribution of the mutant virus was delayed by 5-6 days as compared with the wild-type one. On evidence of RNA sequencing in the mutant progeny, Glu50 of the coat protein was substituted with Lys after passage I to compensate for the loss of the positive charge at position 53. Electron microscopy revealed atypical inclusions (rodlike structures, multiple electron-dense globular particles) in the nuclear interchromatin space of leaf mesophyll cells infected with the mutant but not with the wild-type virus.     

Phosphate permease gene as a marker for the species-specific identification of the toxigenic fungus Fusarium cerealis

A PCR-based system has been developed for highly specific identification of the phytopathogenic fungus Fusarium cerealis on the basis of the nucleotide sequence of the phosphate permease gene. Sequencing and the following analysis showed that this gene demonstrated a high degree of polymorphism and can be used for both phylogenetic studies and as a marker for specific primer design. Investigation of the specificity of the designed primers confirmed the lack of cross-reactivity with DNA of closely related fungi species of the Fusarium genus. The qPCR assay demonstrated high sensitivity of the test system, which was 10 pg of the specific DNA per reaction.     

Detection of staphylococcal enterotoxin a by phage display mediated immuno-PCR method

A method of staphylococcal enterotoxin A (SEA) detection in pasteurized milk using recombinant miniantibodies exposed on phage particles was developed. Miniantibodies bind to the antigen, while phage DNA serves as a matrix in polymerase chain reaction (PCR). The SEA detection limit in milk by a phage display mediated immuno-PCR method is 100 pg/mL that is much lower than the level of toxic and allergic dose.